Thermal management in radical induced cationic frontal polymerisation for optimised processing of fibre reinforced polymers

Radical induced cationic frontal polymerisation (RICFP) is considered a promising low energy method for processing of fibre reinforced polymers (FRPs). Optimisation of the local heat balance between reinforcement, epoxy resin and the surrounding mould is required to pave the way for its adaptation to an industrial processing method for high volume fraction structural fibre reinforced composites. In this work, we investigate several methods to control the governing heat balance in RICFP-processing of FRPs. Heat generation was controlled by tuning the initiator concentration while limitation of heat losses using highly insulating moulds was found beneficial to the front characteristics and resulting curing degrees. An optimised mould configuration allowed for self-sustaining RICFP in FRPs with fibre volume fractions (Vfs) up to 45.8%, exceeding previously reported maxima of similar systems. A process window was moreover established relating the Vf and required heat generation to the potential formation of a self-sustaining or supported front.